Partial dopamine-D 2 receptor agonist plus serotonin and/oder noradrenaline inhibitor activity

ABSTRACT

The invention relates to the use of a compound or a combination of compounds having partial dopamine-D 2  receptor agonistic activity and serotonin and/or noradrenaline reuptake inhibitory activity, for the preparation of a pharmaceutical composition for the treatment of psychiatric and/or neurologic disorders caused by disturbances of the major monoaminergic (dopamine, serotonin and/or nordrenaline) systems or that can be treated via manipulation of those systems.

The invention relates to the use of a compound or a combination ofcompounds having partial dopamine-D₂ receptor agonistic activity andserotonin and/or noradrenaline reuptake inhibitory activity, for thepreparation of a pharmaceutical composition for the treatment ofpsychiatric and/or neurologic disorders caused by disturbances of themajor monoaminergic (dopamine, serotonin and/or nordrenaline) systems orthat can be treated via manipulation of those systems, said disordersselected from the group consisting of: schizophrenia and other psychoticdisorders; mood disorders such as bipolar I disorders, bipolar IIdisorders and unipolar depressive disorders like minor depression,seasonal affective disorder, postnatal depression dysthymia and majordepression; anxiety disorders including panic disorder (with or withoutagoraphobia), social phobia, obsessive compulsive disorder (OCD, with orwithout co-morbid chronic tic or schizotypal disorder), posttraumaticstress disorder and generalized anxiety disorder (GAD); substancerelated disorders, including substance use disorders (like dependenceand abuse) and substance induced disorders (like substance withdrawal);pervasive development disorders including autistic disorder and Rett'sdisorder; attention deficit and disruptive behavior disorders such asattention deficit hyperactivity disorder (ADHD); impulse controldisorders like pathological gambling; eating disorders like anorexianervosa and bulimia nervosa; tic disorders like Tourette's disorder;restless legs syndrome; disorders characterized by impairment ofcognition, memory and/or co-morbid psychiatric disorders andneurorehabilitation (post-traumatic brain lesions).

Dopaminergic neurones, particularly those of the nigrostriatal pathwayare involved in the fine-tuning of control of movement. Degeneration ofthis pathway may lead to neurological disorders. However, dopamine inthe brain is also part of the limbic system, including the limbiccortex, amygdala, nucleus accumbens, septum, olfactory tubercle andfrontal cortex. Therefore disturbances in these systems are linked todisturbances of perception and especially of emotional behavior.

Serotonergic and noradrenergic projections regulate many behavioural andaffective states that are disturbed in psychiatric disorders. Serotoninand noradrenaline reuptake inhibitors and also compounds with these twoactivities combined, are widely used for the treatment of depressive andanxiety disorders.

In contrast to the use of full dopamine-D₂ receptor agonists orantagonists, the use of partial dopamine-D₂ receptor agonists offers adynamic medication that self-adjusts on a moment-to-moment basis to theendogenous state of the patient. Thus, it provides the desired flexiblemodulation of the dopamine system and avoidance of the many adverseeffects caused either by treatment using full dopamine-D₂ receptoragonists like bromocriptine (hallucinations, nausea, vomiting,dyskinesia, orthostatic hypotension, somnolescence) or full dopamine-D₂receptor antagonists like haloperidol (emotional blunting, dysphoria,tardive dyskinesia). Because of these many adverse effects, fullagonists and antagonists have found only very limited use in the therapyof depressive and anxiety disorders.

Partial dopamine-D₂ receptor agonists not only show a flexiblemodulation and a favourable side-effect profile, they also have apronounced anxiolytic profile in relevant animal models (Drugs of theFuture 2001, 26(2): 128-132). Noradrenaline and/or serotonin reuptakeinhibitors have a more pronounced antidepressive profile.

It has now been found that when both activities are combined in onepharmaceutical preparation, such preparations allow for a completetreatment of all disease symptoms (e.g. positive and negative symptomsof schizophrenia), and are particularly useful for the treatment ofpsychiatric disorders involving hypo-, hyper- or fluctuating activity ofthe dopaminergic system. Such preparations can also be used to treatpatients suffering from mania, anxiety or depression in combination withpsychotic episodes.

Partial dopamine-D₂ receptor agonists, according to the presentInvention, are compounds that—when tested in a concentration responserange—achieve at least 20% but not more than 60% activation in thefunctional cAMP cell based assay (as described below) even in very highconcentrations such as 100 times the EC₅₀-value of the compound.Compounds which give less than 20% or more than 60% activation in thisfunctional dopamine-D₂ receptor assay are regarded as full antagonistsand agonists, respectively, and are prone to cause the adverse effectsassociated with dopamine-D₂ receptor antagonists and agonists. Partialdopamine-D₂ receptor agonists will act as an agonist in cases when theendogenous synaptic tone of dopamine is low, or in the the presence of afull dopamine-D₂ receptor antagonist, and will act as an antagonist incases when the endogenous synaptic tone of dopamine is high, or in thepresence of a full dopamine D₂ receptor agonist. This is illustrated inFIG. 1, in a graphical representation of the hypothetical relationshipbetween varying levels of endogenous agonist (e.g. dopamine) in absenceand presence of a partial agonist showing that primarily the amplitudeis affected, ensuring increased tone at low ambient dopamineconcentrations, and limiting peak effects at high levels.

Like full agonists, partial dopamine-D₂ receptor agonists in general areactive in sensitized systems. They Induce contralateral turning in ratswith unilateral 6-hydroxy-dopamine (6-OHDA) lesions in the substantianigra pars compacta. In MPTP-treated common marmosets they producepotent and long-lasting reversal of motor symptoms (Drugs of the Future2001, 26(2): 128-132). In contrast to full agonists, however, partialdopamine-D₂ agonists are substantially less active in non-sensitizedsystems: they hardly reverse reserpine induced hypolocomotion in rats.

It has now been found that compounds having partial dopamine-D₂ activityand serotonin and/or noradrenaline reuptake inhibitory activity in onemolecule, or pharmaceutical preparations consisting of combinations ofcompounds having partial dopamine-D₂ activity and serotonin and/ornoradrenaline reuptake inhibitory activity, simultaneously show allthree (respectively two) activities in vivo, as was demonstrated bymicrodialysis experimentation.

For the treatment of CNS disorders involving an overactive dopaminergicsystem a pharmaceutical preparation combining partial dopamine-D₂receptor agonistic activity having low intrinsic functional activitywith serotonin and/or noradrenaline reuptake inhibitory activity Isrecommended. In case of a disorder involving dopamine insufficiency apharmaceutical preparation combining partial dopamine-D₂ receptoragonistic activity with high intrinsic functional activity and serotoninand/or noradrenaline reuptake activity according to the invention hasconsiderable advantages.

Surprisingly, it has now been found that pharmaceutical preparations ofone or more compounds combining an intrinsic functional dopamineactivity of at least 20% and at the most 60% in combination withserotonin and/or noradrenaline reuptake activity, are useful for thetreatment of all psychiatric disorders for which dynamic readjustment ofthe dopamine system is required.

Disorders characterized by dynamic fluctuations in dopamineneurotransmission like bipolar depression and addiction will profit inparticular from the flexible adjustment of the dopamine system by thepartial dopamine-D₂ receptor agonists in the pharmaceutical preparation.Combining this “dopaminergic neurotransmission stabilising” activitywith serotonin and/or noradrenaline reuptake inhibitory activity willenhance antidepressive and anxiolytc efficacy.

In conclusion, the present invention demonstrates that the broadefficacy of pharmaceutical preparations, combining partial dopamine-D₂receptor agonistic activity with serotonin and/or noradrenaline reuptakeinhibitory activity in animal models predictive for antipsychotic,antidepressive and anxiolytic activity, clearly underlines the usepotential of the dynamic modulation of dopamine mediatedneurotransmission in combination with the antidepressive action of 5-HTand/or NA inhibitory activity for the treatment of many co-morbidpsychiatric disorders.

EXAMPLES

Combinations of compounds which can be used according to the inventionare preparations containing in general terms:

-   (1) a partial dopamine-D₂ agonist (defined as above), a specific    5-HT reuptake inhibitor and/or a specific noradrenaline reuptake    inhibitor.-   (2) a partial dopamine-D₂ agonist and a compound having both 5-HT-    and noradrenaline reuptake activity-   (3) a partial dopamine-D₂ agonist which Is also a specific 5-HT    reuptake inhibitor combined with a specific noradrenaline reuptake    inhibitor-   (4) a partial dopamine-D₂ agonist which is also a specific    noradrenaline reuptake inhibitor combined with a specific 5-HT    reuptake inhibitor

Specific examples of compounds which can be used in combinationpreparations according to the invention are (but are not restricted to)the specific serotonin reuptake inhibitors (SSRI's): alaproclate,citalopram, fluoxetine, fluvoxamine, litoxetine, nefazodone, paroxetine,sertraline, trazodone and zimelidine; the specific noradrenalinereuptake inhibitors (SNRI's): amoxapine, desipramine, maprotiline,mazindol, nisoxetine, nomifensine, nortriptiline, protriptiline,reboxetine and tomoxetine; the compounds with combined serotonin andnoradrenaline reuptake inhibitory activity: chlorimipramine, duloxetine,imipramine, indatraline, milnacipran, S-33005, sibutramine andvenlafaxine; and the partial dopamine-D₂ agonists: BP 897,dihydroergocristine, dihydroergotamine, preclamol ((S)-(−)-3-PPP),terguride, bifeprunox and SLV 308 (Structure (1) of examples, in whichR═CH₃).

Single compounds which can be used according to the invention arecompounds that are both partial dopamine-D₂ agonists and specific 5-HTreuptake inhibitors, for instance phenylpiperazine derivatives with theformula (1):

wherein R is consisting of moieties (a), (b), (c), (d) or (e) and saltsthereof.

Single compounds which can be used according to the invention arefurthermore compounds that have all three activities: partialdopamine-D₂ agonism, 5-HT reuptake inhibition and NA reuptakeinhibition, for instance the phenylpiperazine derivatives with thestructures given below:

Pharmacologically acceptable acids with which the compounds of theinvention can form suitable acid addition salts are for examplehydrochloric acid, sulphuric acid, phosphoric acid, nitric acid, andorganic acids such as citric acid, fumaric acid, maleic acid, tartaricacid, acetic acid, benzoic acid, p-toluene sulphonic acid,methanesulphonic acid and naphthalene sulphonic acid.

The compounds are their acid addition salts can be brought into formssuitable for administration by means of suitable processes usingauxiliary substances such as liquid and solid carrier materials.

Examples 1a-1e and 2a-2c can be synthesized as described in WO00EP08190.

Pharmacological Testing

The in vitro functional activity at dopamine-D₂ receptors, Including theintrinsic activity (ε) of the compounds which can be used according tothe invention as well as relevant reference compounds was measured bytheir ability to inhibit forskolin-induced [³H]cAMP accumulation.Serotonin and noradrenaline reuptake inhibitory activity was measured Inrat brain synaptosomes. Protocols are described below, and the resultsobtained are presented in table 1.

Inhibition of Forskolin-Induced [³H]-cAMP Accumulation

Human dopamine D_(2,L) receptors were cloned in fibroblast cell lineCHO-K1 cells and obtained from Dr. Grandy, Vollum Institute, Portland,Oreg., USA. CHO cells were grown in a Dulbecco's modified Eagle's medium(DMEM) culture medium, supplemented with 10% heat-inactivated fetal calfserum, 2 mM glutamine, 1 mM pyruvate, 5000 units/ml penicillin, 5000μg/ml streptomycin and 200 μg/ml at 37° C. in 93% air/7% CO₂. Forincubation with test compounds, confluent cultures grown in 24 wellsplates were used. Each condition or substance was routinely tested inquadruplicate. Cells were loaded with 1 μCi [³H]-adenine in 0.5 mlmedium/well. After 2 hours, cultures were washed with 0.5 ml PBScontaining 1 mM of the phosphodiesterase inhibitorisobutylmethylxanthine (IBMX) and incubated for 20 min with 0.5 ml PBScontaining 1 mM IBMX and forskolin with or without test compound. Afteraspiration the reaction was stopped with 1 ml trichloroacetic acid 5%(w/v). The [³H]-ATP and [³H]-cAMP formed in the cellular extract wereassayed as described by Solomon Y, Landos C, Rodbell M, 1974, A highlyselective adenylyl cyclase assay, Anal Biochem 58:541-548 and Weiss S,Sebben M, Bockaert J J, 1985, Corticotropin-peptide regulation ofintracellular cyclic AMP production in cortical neurons in primaryculture, J Neurochem 45:869-874. 0.8 ml Extract was passed over Dowex(50WX-4 200-400 mesh) and aluminumoxide columns, eluted with water and0.1M imidazole (pH=7.5). Eluates were mixed with 7 ml Insta-gel andradioactivity was counted with a liquid scintillation counter. Theconversion of [³H]-ATP into [³H]-cAMP was expressed as the ratio inpercentage radioactivity in the CAMP fraction as compared to combinedradioactivity in both cAMP and ATP fractions, and basal activity wassubtracted to correct for spontaneous activity.

Reference and test compounds were all obtained as 10 mM stock solutionsin 100% DMSO, and diluted in PBS/IBMX to final concentrations.Typically, compounds were used in concentrations that ranged from 10⁻¹⁰Mto 10⁻⁵M. From quadruplicate data counts, the mean was taken as anestimate for drug-induced, receptor-mediated effects at specified secondmessenger accumulation, expressed as percentage of control values(forskolin-stimulated cAMP accumulation, subtracted by basal activity).By using the non-linear curve-fitting program INPLOT or the Excel-add-inXL-Fit, mean values were plotted against drug concentration (in molar)and a sigmoid curve (four-parameter logistic curve) was constructed. Themaximal forskolin-induced stimulated conversion is taken as maximumvalue and the maximal Inhibition (usually at drug concentrations 10⁻⁶ Mor 10⁻⁵ M) as minimum and these values were fixed during the fittingprocess. Thus, concentrations of the compound, causing 50% of themaximally obtained inhibition of forskolin-induced cAMP accumulation(EC₅₀), are averaged over several experiments and presented as meanpEC₅₀±SEM in graphs and tables. Antagonist potency is assessed byco-incubating cells with a fixed agonist concentration and specifiedantagonist concentrations. Curve fitting procedures are identical tothose used for estimating EC₅₀ values. Thus IC₅₀ values, i.e. thatconcentration that is able to achieves 50% of maximal antagonism thatcan be achieved by this compound. IC₅₀ values are corrected using aCheng-Prussoff equation, correcting it for agonist concentration andEC₅₀ values that is obtained In the same experiment. Thus,K_(b)=IC₅₀/(1+[agonist]/EC₅₀, agonist). The corresponding pA₂ value is−log (K_(b)). Concentration-response curve fitting allows estimation ofpEC₅₀ values and of maximal achievable effect (intrinsic activity orefficacy (ε). A full receptor agonist has ε=1, a full receptorantagonist has ε=0, and a partial receptor agonist has an intermediateintrinsic activity. Compound selection of partial dopamine D₂ receptoragonists therefore is completely dependent on concentration-responserelationships as measured by CAMP accumulation in CHO-D_(2,L) cells andevaluation of ε, with a desired range between 0,20 and 0,60.

Several compounds, turn out to only partially inhibit formation of CAMP,e.g. terguride, precdamol ((S)-(−)-3-PPP) and SLV308. These compoundshave been tested at CHO cells, stably expressing human dopamine D₂receptors in a concentration-dependent manner and none of thesecompounds were able to attenuate CAMP formation by more than 60% ascompared to quinpirole (100%). Thus, these compounds are identified aspartial agonists. That SLV 308 is a truly partial agonist was found byapplying SLV 308 itself at the dopamine receptors or in presence of thefull agonist quinpirole. Thus, whereas SLV 308 is able to induce effects(inhibition of CAMP formation), it can also block the actions of a fullagonist in a concentration dependent manner (pEC₅₀ 8.0; pA₂ 8.4). InFIG. 2 the effects of SLV 308 and other reference compounds at humandopamine D₂ receptors are shown. The upper panel illustrates the agonistproperties of compounds: thus, quinpirole and talipexole are fullagonists, whereas SLV 308 and terguride are partial agonists. The lowerpanel Illustrates antagonist effects against the reference agonistquinpirole. Thus, whereas haloperidol is a full antagonist at D₂receptors, both SLV 308 and terguride are found as “partialantagonists”, blocking only half of the maximal biological effect.Agonism and antagonism are in equilibrium.

In Vitro Functional Inhibition of [³H]-serotonin Reuptake

Male rats (Wistar Hsd/Cpb: WU; 175-200 g) were decapitated, the cerebralhemispheres were rapidly removed and a P2-synaptosomal fraction wasprepared. Synaptosomes were pre-incubated in absence or presence of thetest compound for 15 min at 37° C., in a medium containing the monoamineoxidase inhibitor pargyline (7 μM). Subsequently, the synaptosomes wereexposed to [³H]-serotonin (0.2 mM final concentration) for 10 min.

[³H]-serotonine uptake was stopped by filtration with a harvester andthe non-incorporated radioactivity was removed by an extensive washingprogramme. The filter plates with synaptosomes were dehydrated and theamount of [³H]-serotonin present was determined by Betaplate liquidscintillation counting. Inhibitory effects on the uptake of the[³H]-serotonin were expressed as pIC₅₀ value, that is the negativelogarithm of the concentration at which half maximal inhibition ofradiolabeled neurotransmitter uptake is achieved. pIC₅₀ values given inTable 2 are mean values of 2-9 experiments performed in duplicate. Testcompounds, 10⁻² M dissolved in DMSO, were diluted in Krebs Ringer bufferto the test concentrations of 10⁻⁸ to 10⁻⁵ M. Further experimentaldetails (like e.g. buffer compositions) are described by J. T. Coyle andS. H. Snyder, 1969, Catecholamine uptake by synaptosomes in homogenatesof rat brain; stereospecificity in different areas, J. Pharmacol. Exp.Ther. 170, 221-231.

In vitro functional inhibition of [³H]-noradrenalin reuptake Male rats(Wistar Hsd/Cpb: WU; 175-200 g) were decapitated, the hypothalamus wasrapidly removed and a crude synaptosomal fraction was prepared.Synaptosomes were pre-incubated in absence or presence of the testcompound for 10 min at 37° C., in a medium containing the monoamineoxidase inhibitor pargyline (7 μM). Subsequently, the synaptosomes wereexposed to [³H]-noradrenaline (0.4 mM final concentration) for 15 min.

[³H]-noradrenaline uptake was stopped by filtration with a harvester andthe non-incorporated radioactivity was removed by an extensive washingprogramme. The filter plates with synaptosomes were dehydrated and theamount of [³H]-noradrenaline present was determined by Betaplate liquidscintillation counting. Inhibitory effects on the uptake of the[³H]-noradrenaline were expressed as pIC₅₀ value, that is the negativelogarithm of the concentration at which half maximal inhibition ofradiolabeled neurotransmitter uptake is achieved. pIC₅₀ values given inTable 2 are mean values of 2-9 experiments performed in duplicate. Testcompounds, 10⁻² M dissolved in DMSO, were diluted in Krebs Ringer bufferto the test concentrations of 10⁻⁸ to 10⁻⁵ M. Further experimentaldetails (like e.g. buffer compositions) are described by J. T. Coyle andS. H. Snyder, 1969, Catecholamine uptake by synaptosomes in homogenatesof rat brain; stereospecificity in different areas, J. Pharmacol. Exp.Ther. 170, 221-231. TABLE 1 In vitro functional activity ar cloned humandopamine D_(2,L) receptors as measured by accumulation of radiolabeledcAMP (potency: pEC₅₀, intrinsic activity ε) and in vitro functionalactivity on serotonin and noradrenaline reuptake sites of pure compoundsand combination preparations. cAMP accum. 5-HT_(uptake) NA_(uptake)Compound class Compound pEC₅₀* ε* pIC₅₀ pIC₅₀ Full dopamine-D₂ agonistquinpirole 7.6 1.00 <5.0 <5.0 Full dopamine-D₂ agonist talipexole 7.41.00 <5.0 <5.0 Partial dopamine-D₂ agonist terguride 9.4 0.38 <5.0 <5.0Partial dopamine-D₂ agonist preclamol 6.4 0.36 <5.0 5.3 Partialdopamine-D₂ agonist bifeprunox 7.8 0.20 4.8 4.6 Partial dopamine-D₂agonist SLV 308 7.5 0.55 <5.0 <5.0 Specific 5-HT reuptake inh.fluvoxamine <6.0 0.10 6.9 5.3 Specific 5-HT reuptake inh. fluoxetine 5.95.0 Specific 5-HT reuptake inh. paroxetine <6.0 0.36 7.4 <5.0 SpecificNA reuptake inh. DMI <6.0 0.12 5.2 7.1 Specific NA reuptake inh.reboxetine <6.0 0.09 5.0 7.2 Mixed 5-HT/NA reuptake inh. milnacipran<6.0 0.21 6.6 5.5 Partial D₂ agonist + SRI example 1a <6.0 0.27 6.9 <5.0Partial D₂ agonist + SRI example 1b 0.27 <5.0 5.2 Partial D₂ agonist +SRI example 1c 6.8 0.53 7.6 <5.0 Partial D₂ agonist + SRI example1d >9.0 0.56 6.4 <5.0 Partial D₂ agonist + SRI example 1e >9.0 0.60 6.6<5.0 Partial D₂ ago. + SRI + NRI example 2a 6.0 0.24 6.3 5.3 Partial D₂ago. + SRI + NRI example 2b 8.5 0.62 6.0 5.7 Partial D₂ ago. + SRI + NRIexample 2c 8.8 0.79 5.1 5.4*pEC₅₀: −log of the concentration at which half of the maximallyachievable effect is obtained for that particular drug. Its intrinsicactivity,*ε, is expressed as a fraction of full agonism (ε = 1), which isachieved by a full agonist such as quinpirole.

Microdialysis allows an insight into changes in neurotransmitters andtheir metabolites in the brain extracellular space in discrete brainregions in awake freely moving animals. Extracellular levels ofneurotransmitters mirror the neuronal activity (neurotransmitterrelease) in these brain regions and can be influenced by selectivereceptor agonists and antagonists, uptake inhibitors, etc. The in vivoeffects of the (mixtures of) compounds of the invention on dopamine,serotonin and noradrenalin levels were determined by microdialysisaccording to the protocol given below:

Dopamine and Serotonin Measurements by In Vivo Microdialysis

Surgery. Male wistar rats, weighing 280-300 g, were anaesthetized byhalothane-narcosis (1.5% halothane in NO₂/O₂ 2:1). Antibacterial agentsand analgesics were administered prior to (Baytril (150 μl/rat i.m.))and after (Temgesic (0.005-0.01 mg/kg i.m. non-diluted/rat)) surgery.Following placement in a stereotactic frame, the skull is exposed and a1 mm bore-hole is drilled through the bone above the nucleus accumbens(co-ordinates from interaural point (mm): anterior-posterior +10.5,mediolateral −2.1 and dorsoventral −6.5 at a 80 angle (from dura)) inthose animals where determination of dialysate dopamine and serotoninlevels is required. In other animals, the skull is exposed and a 1 mmbore-hole is drilled through the bone above the prefrontal cortex(co-ordinates from bregma (mm): anterior-posterior +3.2, mediolateral0.6 and dorsoventral −1.5 at a 0° angle (from dura)) in those animalswhere determination of dialysate noradrenaline levels is required.Smaller bore holes are made and three screws are inserted within theskull. The intracerebral guide cannula (CMA, Carnegie) is loweredthrough the hole until the tip is immediately above the nucleusaccumbens or prefrontal cortex. The guide together with the screws arecemented onto the bone with dental cement and the surrounding skinsutured. Animals are allowed to recover at least six days prior tomicrodialysis experimentation.

Microdialysis experimentation. On the day of the experimentmicrodialysis probes (CMA 12, 0.5 mm outer diameter, Stockholm, Sweden)are inserted through the guide cannula into the nucleus accumbens (2 mmmembrane length) or prefrontal cortex (4 mm membrane length). The Inletof the probe is connected with low volume tubing (F.E.B-tubing, 1.2μl/10 cm, Carnegie) via a liquid-swivel (dual channel; Instech, UK) on acounterbalanced arm, to a syringe-pump (Harvard, 10 channel). Thesyringe pump delivers the dialysis fluid (147 mM NaCl, 4 mM KCl, 1.2 mMCaCl₂ and 0.7 mM MgCl₂) at a constant flow of 2 μl/min. The outlet ofthe probe is connected with low volume tubing via the liquid swivel to aCMA 140 fraction collector. The tubing is supported by a stainless steelwire which leads from the swivel down to a clip, which fits to a collararound the neck of an animal. Dopamine, serotonin and noradrenalinelevels are stable 16 hours after probe insertion, after which dialysissampling begins. Samples are collected at a flow rate of 2 μl/min at 20min intervals (40 μl volume) in vials containing 50 μl of aHCOOH/cysteine solution (0.02M/0.2 w/v %) to prevent oxidation of thecompounds. Following a baseline period of 5 samples, drugs areadministered systemically and at least a further 8 samples collected.All samples were stored post-collection on dry ice and frozen at 80° C.prior to analysis by high-performance liquid chromatography (HPLC)coupled to electrochemical detection described below.

Analysis of dialysate dopamine and serotonin. Samples are analysed usinga reversed phase column (Supelcosyl LC-8 DB, 25 cm×4.6 mm, 5 μm particlediameter, Supelco), maintained at 45° C. with a column-oven (Mistral;Spark, The Netherlands), and a Gilson (model 231401 or 232-401) orHP1100 auto-injector with cooling device (10° C.). The pump (HewlettPackard, model 1050 or HP1100) operates at a flow of 1 ml/min. Themobile phase consisted of (mM) 50 HAc/NaAc (3:1), 1.46 HSA, 0.27 EDTAand 16% (v/v) methanol. The final pH was adjusted to 4.9 with 1N NaOH.Dopamine and serotonin are electrochemically detected with an EG&G(model 400, Princeton Applied Research) controller equipped with aglassy carbon working electrode (VT-03; Antec, Leiden, the Netherlands).The potential is set at 600 mV versus an Ag/AgCl reference electrode.The output is recorded on a computer equipped with Hyperchem™(Hewlett-Packard Inc.) which measures peak height values. Calculations(μg/20 min) are made using peak height values of analysed standardsolutions containing known amounts of dopamine and serotonin. Analysisof dialysate dopamine and noradrenaline. The samples are analysed usinga reversed phase column (Supelcosyl LC-18 DB, 150 mm×4.6 mm, dp=3 μm,Supelco), maintained at 25° C. with a column-oven (Mistral; Spark, TheNetherlands), and a Gilson (model 231401 or 232401) or HP1100autoinjector with cooling device (10° C.). The pump (Hewlett Packard,model 1050 or HP1100) operates at a flow of 1 ml/min. The basal mobilephase consists of: 50 mM NaAc, and 0.27 mM EDTA. The final concentrationof 1-octanesulfonic acid (NOS) and methanol, as well as the final pH(adjusted with HAc), vary with the different brain areas underexamination. The compounds are electrochemically detected with an EG&G(model 400, Princeton Applied Research) controller equipped with aglassy carbon working electrode (VT-03; Antec, Leiden, the Netherlands).The potential is set at 450 mV versus a Hyref reference electrode. Theoutput is analyzed and archived with an Hewlett Packard Chemstationwhich calculates concentration (pg/20 min) on peak height values.Calculations are made using peak height values of analysed standardsolutions containing known amounts of the compounds (external standardmethod). The results obtained are given in table 2: TABLE 2 In vivomicrodialysis data on dopamine, serotonin and noradrenaline levels.[dopamine] [serotonin] [noradren] Compound class Compound ED₇₅ mg/kgED₁₅₀ mg/kg ED₁₅₀ mg/kg Full dopamine-D₂ agonist quinpirole 0.04 >3 Fulldopamine-D₂ agonist talipexole <0.1 >10 partial dopamine-D₂ agonistterguride >10 >10 partial dopamine-D₂ agonist preclamol 14.46 >30partial dopamine-D₂ agonist bifeprunoxx >10 >10 ¹ partial dopamine-D₂agonist SLV 308 0.04 0.45 ¹ 0.53 Specific 5-HT reuptake inh.fluvoxamine >30 ² 1.28 Specific 5-HT reuptake inh paroxetine >10 <10Specific NA reuptake inhib. DMI >3 >3 1.64 Specific NA reuptake inhib.reboxetine >3 >3 <3.0 Mixed 5-HT/NA reuptake inh. milnacipran >30 5.52.41 Comb. part D₂ afonist + SRI SLV308 + fluvox 6.41 >10 Comb. part D₂agonist + NRI SLV308 + rebox <0.3 0.77 ¹ <0.3 Comb. part D₂ ago + SRI +NRI SLV308 + milnaci <3.0 >30 <3.0 Partial D₂ agonist + SRI example 1a8.14 2.52 Partial D₂ agonist + SRI example 1c 3.92 14.79 Partial D₂ago. + SRI + NRI example 2a >30 ² 5.44 <1.0Table 2. Effect of full and partial D₂ agonist alone in combination witheither a serotonin reuptake inhibitor (SRI) or noradrenaline reuptakeinhibitor (NRI) on dialysate dopamine and serotonin in the nucleusaccumbens and noradrenaline levels in the prefrontal cortex of the awakefreely moving rat. Values in bold are p.o., values in italic are i.p.¹ED₇₅,²ED₁₅₀.

1. Use of a compound or a combination of compounds having partialdopamine-D₂ receptor agonistic activity and noradrenaline reuptakeinhibitory activity and optionally serotonin reuptake inhibitoryactivity for the preparation of a pharmaceutical composition for thetreatment of psychiatric and/or neurologic disorders caused bydisturbances of the dopamine, serotonin and/or noradrenaline systems orthat can be treated via manipulation of those systems.
 2. Use as claimedin claim 1 characterized in that said compound or combination ofcompounds have partial dopamine-D₂ receptor agonistic activity andnoradrenergic reuptake inhibitory activity.
 3. Use as claimed in claim 1characterized in that said compound has partial dopamine-D₂ receptoragonistic activity and noradrenaline reuptake inhibitory activity andoptionally serotonin reuptake inhibitory activity combined in onemolecule.
 4. Use as claimed in claim 1 characterized in that saidcombination of compounds has partial dopamine-D₂ receptor agonisticactivity and noradrenaline reuptake inhibitory activity and optionallyserotonin reuptake inhibitory activity.
 5. Use as claimed in claim 2characterized in that said compound has partial dopamine-D₂ receptoragonistic and noradrenaline reuptake inhibitory activity combined in onemolecule.
 6. Use as claimed in claim 2 characterized in that saidcombination of compounds has partial dopamine-D₂ receptor agonisticactivity and noradrenaline reuptake inhibitory activity.
 7. Use asclaimed in any of the claims 1-6 characterized in that said psychiatricand/or neurologic disorders caused by disturbances of the majormonoaminergic (dopamine, serotonin and/or nordrenaline) systems or thatcan be treated via manipulation of those systems, are selected from thegroup consisting of: schizophrenia and other psychotic disorders; mooddisorders such as bipolar I disorders, bipolar II disorders and unipolardepressive disorders like minor depression, seasonal affective disorder,postnatal depression, dysthymia and major depression; anxiety disordersincluding panic disorder (with or without agoraphobia), social phobia,obsessive compulsive disorder (OCD, with or without co-morbid chronictic or schizotypal disorder), posttraumatic stress disorder andgeneralized anxiety disorder (GAD); substance related disorders,including substance use disorders (like dependence and abuse) andsubstance induced disorders (like substance withdrawal); pervasivedevelopment disorders including autistic disorder and Rett's disorder;attention deficit and disruptive behavior disorders such as attentiondeficit hyperactivity disorder (ADHD); impulse control disorders likepathological gambling; eating disorders like anorexia nervosa andbulimia nervosa; tic disorders like Tourette's disorder; restless legssyndrome; disorders characterized by impairment of cognition, memoryand/or co-morbid psychiatric disorders and neurorehabilitation (posttraumatic brain lesions).
 8. Use as claimed in any of the claims 1-6characterized in that said composition is used for the treatment ofschizophrenia and other psychotic disorders.
 9. Use as claimed in any ofthe claims 1-6 characterized in that said composition is used for thetreatment of mood disorders such as bipolar I disorders and bipolar IIdisorders.
 10. Use as claimed in any of the claims 1-6 characterized inthat said composition is used for the treatment of unipolar depressivedisorders like minor depression, seasonal affective disorder, postnataldepression, dysthymia and major depression.
 11. Use as claimed in any ofthe claims 1-6 characterized in that said composition is used for thetreatment of anxiety disorders including panic disorder (with or withoutagoraphobia).
 12. Use as claimed in any of the claims 1-6 characterizedin that said composition is used for the treatment of social phobia. 13.Use as claimed in any of the claims 1-6 characterized in that saidcomposition is used for the treatment of obsessive compulsive disorder(OCD, with or without co-morbid chronic tic or schizotypal disorder).14. Use as claimed in any of the claims 1-6 characterized in that saidcomposition is used for the treatment of posttraumatic stress disorder.15. Use as claimed in any of the claims 1-6 characterized in that saidcomposition is used for the treatment of generalized anxiety disorder(GAD).
 16. Use as claimed in any of the claims 1-6 characterized in thatsaid composition is used for the treatment of substance relateddisorders, including substance use disorders (like dependence and abuse)and substance induced disorders (like substance withdrawal).
 17. Use asclaimed in any of the claims 1-6 characterized in that said compositionis used for the treatment of pervasive development disorders includingautistic disorder and Rett's disorder
 18. Use as claimed in any of theclaims 1-6 characterized in that said composition is used for thetreatment of attention deficit and disruptive behavior disorders such asattention deficit hyperactivity disorder (ADHD).
 19. Use as claimed inany of the claims 1-6 characterized in that said composition is used forthe treatment of impulse control disorders like pathological gambling.20. Use as claimed in any of the claims 1-6 characterized in that saidcomposition is used for the treatment of eating disorders like anorexianervosa and bulimia nervosa.
 21. Use as claimed in any of the claims 1-6characterized in that said composition is used for the treatment of ticdisorders like Tourette's disorder.
 22. Use as claimed in any of theclaims 1-6 characterized in that said composition is used for thetreatment of restless legs syndrome.
 23. Use as claimed in any of theclaims 1-6 characterized in that said composition is used for thetreatment of disorders characterized by impairment of cognition, memoryand/or co-morbid psychiatric disorders and neurorehabilitation (postbrain lesions).
 24. Method for the preparation of a compositioncharacterized in that it brings a compound having partial dopamine-D₂receptor agonistic activity and noradrenaline reuptake inhibitoryactivity and optionally serotonin reuptake inhibitory activity, or acombination of compounds having partial dopamine-D₂ receptor agonisticactivity and noradrenaline reuptake inhibitory activity and optionallyserotonin reuptake inhibitory activity, into a form suitable foradministration.
 25. A composition comprising a compound having partialdopamine-D₂ receptor agonistic activity and noradrenaline reuptakeinhibitory activity and optionally serotonin reuptake inhibitoryactivity, or a combination of compounds having partial dopamine-D₂receptor agonistic activity and noradrenaline reuptake inhibitoryactivity and optionally serotonin reuptake inhibitory activity, in aform suitable for administration.
 26. Use as claimed in any of theclaims 1-23 characterized in that said partial dopamine-D₂ agonisticactivity intrinsically is between 20% and 60% of that of a full agonistin the inhibition of forskolin-induced [³H]-cAMP accumulation.
 27. Useas claimed in any of the claims 1-23 characterized in that saidcomposition simultaneously shows partial dopamine-D₂ activity andserotonin and/or noradrenaline reuptake inhibitory activity in in vivomicrodialysis experiments.
 28. Use as claimed in any of the claims 1-23characterized in that said composition simultaneously shows partialdopamine-D₂ activity and serotonin reuptake inhibitory activity in invivo microdialysis experiments.
 29. Use as claimed in any of the claims1-23 characterized in that said composition simultaneously shows partialdopamine-D₂ activity and noradrenaline reuptake inhibitory activity inin vivo microdialysis experiments.